JP3765137B2 - Variable capacity compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable displacement compressor applied to, for example, a vehicle air conditioning system.
[0002]
[Prior art]
In this type of compressor, for example, there is one disclosed in Japanese Patent Laid-Open No. 3-37378. That is, the housing is formed by joining a plurality of housing components, and rotatably holds the drive shaft. The suction chamber, the discharge chamber, and the crank chamber are formed in the housing. The cam plate is accommodated in the crank chamber, and is supported on the drive shaft so as to be integrally rotatable and tiltable. The plurality of cylinder bores are formed in the housing. The single-headed piston is housed in the cylinder bore and connected to the cam plate. The valve forming body is interposed between the housing structure in which the suction chamber and the discharge chamber are formed and the housing structure in which the cylinder bore is formed. The discharge hole is formed corresponding to each cylinder bore in the valve forming body, and communicates the cylinder bore and the discharge chamber. The fixed discharge valve is formed corresponding to the discharge hole in the valve forming body, and opens and closes the discharge hole.
[0003]
Then, the rotational motion of the drive shaft is converted into the reciprocating linear motion of the piston through the cam plate, and after the refrigerant gas is sucked into the cylinder bore from the suction chamber, it is compressed by the action of the fixed discharge valve, and is passed through the discharge hole. To discharge into the discharge chamber. Moreover, the stroke of the piston is changed by adjusting the tilt angle of the cam plate, and the discharge capacity is changed.
[0004]
The solenoid valve is disposed at the inlet of the refrigerant gas in the suction chamber and can block communication between the suction chamber and the external refrigerant circuit. When cooling is unnecessary or when frost is likely to occur in the evaporator on the external refrigerant circuit, the flow of refrigerant gas from the external refrigerant circuit to the suction chamber is stopped by the electromagnetic valve. The refrigerant circulation prevention is achieved. Accordingly, even in such a case, the operation of the compressor may be continued, and an expensive and heavy electromagnetic clutch or the like is provided between the drive shaft and an external drive source such as a vehicle engine that drives the drive shaft. This clutch mechanism is not interposed.
[0005]
By the way, the compressor having the above-described configuration is always operated during operation of the vehicle engine. For this reason, in the refrigerant | coolant circulation prevention state on the external refrigerant circuit mentioned above, power loss and lubrication in each sliding part become a problem. Therefore, when the refrigerant circulation is prevented, the compressor changes the cam plate to the minimum inclination angle to minimize the discharge capacity and reduce the power loss. In addition, the compressor forms a circulation passage through the discharge chamber, the crank chamber, and the suction chamber in a refrigerant circulation prevention state, and each sliding portion is lubricated by a refrigerant gas containing lubricating oil flowing in the passage. Like to do.
[0006]
[Problems to be solved by the invention]
However, in order for the refrigerant gas to circulate through the circulation passage, it is necessary to generate a differential pressure that causes the refrigerant gas to flow between the discharge chamber, the crank chamber, and the suction chamber. For this reason, the compressor regulates the minimum inclination angle of the cam plate not to be zero, and causes the differential pressure between the chambers by continuing the compression of the refrigerant gas even in the refrigerant circulation blocking state. . Therefore, it is difficult to say that the power loss problem described above has been solved, and the compression reaction force acting on the piston when compressing the refrigerant gas presses the piston against the cylinder bore. Wear degradation due to an increase in dynamic resistance becomes a problem.
[0007]
The present invention has been made paying attention to the problems existing in the above-described prior art, and an object of the present invention is to provide a variable capacity compressor capable of reducing power loss in a refrigerant circulation blocking state on an external refrigerant circuit. It is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the refrigerant circulation preventing means for preventing the refrigerant circulation on the external refrigerant circuit and the refrigerant circulation on the external refrigerant circuit are blocked by the refrigerant circulation preventing means. A circulation passage for circulating the refrigerant gas through the discharge chamber, the crank chamber, and the suction chamber, and the valve forming body corresponding to at least one but not all of the discharge holes on the valve forming body. Corresponding to a fixed discharge valve and a discharge hole other than the discharge hole to which the fixed discharge valve corresponds, it can move between an action position that acts as a discharge valve and a non-action position that does not act as a discharge valve A variable capacity compressor comprising a movable discharge valve and unloading means for disposing the movable discharge valve in a non-operating position when refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means. .
[0009]
According to a second aspect of the present invention, the movable discharge valve is configured to be able to contact with and separate from the valve forming body, and the unloading means is disposed inside the housing and connected to the movable discharge valve to A spool is attached so that the spool is movable in the direction of approaching and separating from the body, the control pressure chamber for the spool formed on the back side of the spool, and the movable discharge valve being separated from the valve forming body. An urging means for energizing, a spool supply passage connecting the spool control pressure chamber and a high pressure region higher than the suction pressure region, and a low pressure region lower than the spool control pressure chamber and the high pressure region. When the refrigerant circulation on the external refrigerant circuit is blocked by the connected spool extraction passage and the refrigerant circulation blocking means, the amount of refrigerant gas introduced from the high-pressure region through the spool supply passage and / or the spool Extraction By adjusting the amount of refrigerant gas derived through, in which a spool control means for reducing the pressure of the spool control pressure chamber.
[0010]
According to a third aspect of the present invention, the inclination angle of the cam plate is adjusted by adjusting the pressure in the crank chamber to change the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston. A capacity change air supply passage connecting the discharge pressure region which is a region and the crank chamber which is a low pressure region, a capacity change bleed passage connecting the crank chamber and the suction pressure region, and the capacity change air supply The crank chamber pressure is adjusted by adjusting the opening degree of the passage that is interposed on the passage, and when the refrigerant circulation on the external refrigerant circuit is prevented by the refrigerant circulation prevention means, the opening degree of the passage is increased. And a volume control valve that minimizes the discharge capacity, and the spool bleed passage passes through the capacity control valve, and the capacity control valve constitutes the spool control means.
[0011]
According to a fourth aspect of the present invention, a portion of the capacity changing air supply passage located closer to the discharge pressure region than the capacity control valve is routed through the spool control pressure chamber, and the passage is connected to the spool air supply passage and the spool extraction air. It also serves as a passage.
[0012]
In the invention of claim 5, the inclination angle of the cam plate is adjusted by adjusting the pressure in the crank chamber to change the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston. A capacity change air supply passage connecting the pressure chamber and the crank chamber which is a high pressure region, a capacity change bleed passage connecting the crank chamber and a suction pressure region which is a low pressure region, and the same capacity change bleed passage The crank chamber pressure is changed by adjusting the opening degree of the passage, and when the refrigerant circulation on the external refrigerant circuit is prevented by the refrigerant circulation prevention means, the opening degree of the passage is reduced. A capacity control valve that minimizes the discharge capacity. The spool air supply passage is routed through a capacity control valve, and the capacity control valve constitutes the spool control means.
[0013]
According to a sixth aspect of the present invention, a portion of the capacity changing bleed passage located closer to the suction pressure region than the capacity control valve is routed through the spool control pressure chamber, and the passage is a spool air supply passage and a spool bleed passage. Doubles as
[0014]
In the invention of claim 7, the drive shaft is operatively connected to an external drive source without a clutch mechanism.
(Function)
In the first aspect of the present invention, when refrigerant circulation on the external refrigerant circuit is allowed, for example, the movable discharge valve is disposed at the operating position by the unloading means, and the movable discharge valve and the fixed discharge By the action of the valve, the refrigerant gas sucked into each cylinder bore is compressed and discharged into the discharge chamber.
[0015]
Here, when cooling is unnecessary or when frost is likely to occur in the evaporator on the external refrigerant circuit, the refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means. Then, the movable discharge valve in the operating position is moved to the non-operating position by the unloading means, and the valve is not operated as a discharge valve. Therefore, the refrigerant gas is not compressed in the cylinder bore corresponding to the valve. That is, the compression work is suspended in some cylinder bores, and power loss is reduced.
[0016]
However, even after the movable discharge valve is moved to the non-operating position and does not function as the discharge valve, the operation of the fixed discharge valve as the discharge valve is continued. Therefore, the refrigerant gas in the cylinder bore to which the valve corresponds is compressed and discharged into the discharge chamber. As a result, a differential pressure is generated between the discharge chamber, the crank chamber, and the suction chamber, and the refrigerant gas containing the lubricating oil is circulated in the circulation passage passing through the chambers to lubricate the sliding portions. .
[0017]
As described above, since the refrigerant circulation prevention on the external refrigerant circuit is achieved by the refrigerant circulation prevention means, the compression is performed even when cooling is unnecessary or when frost is likely to occur in the evaporator on the external refrigerant circuit. The machine may continue to operate. Therefore, in the invention of claim 7, the drive shaft is connected to the external drive source without a clutch mechanism, and the compressor is always operated when the external drive source is operated.
[0018]
In the invention of claim 2, when the refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means, the spool control means is configured to reduce the amount of refrigerant gas introduced from the high-pressure region via the spool air supply passage and The pressure in the spool control pressure chamber is lowered below a predetermined value by adjusting the amount of refrigerant gas led to the low pressure region via the spool extraction passage. Accordingly, the spool is moved away from the valve forming body in balance with the urging force of the urging means, and the movable discharge valve is moved from the operating position to the non-operating position.
[0019]
According to a third aspect of the present invention, when refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means, the capacity control valve increases the opening of the capacity changing air supply passage so that the crank from the discharge pressure area is increased. Increase the pressure in the crank chamber by increasing the amount of high-pressure refrigerant gas introduced into the chamber. Therefore, the cam plate is tilted to the minimum inclination angle, and the discharge capacity is minimized.
[0020]
Here, the spool control pressure chamber is connected to the discharge pressure region via the spool air supply passage. Accordingly, the pressure in the discharge pressure region is reduced by minimizing the discharge capacity, and the amount of refrigerant gas introduced from the discharge pressure region into the spool control pressure chamber is reduced. Further, the spool bleed passage is routed through the capacity control valve, and when the capacity control valve increases the opening degree of the capacity changing supply passage, the opening degree of the spool bleed passage increases. Accordingly, the amount of refrigerant gas led out from the spool control pressure chamber to the crank chamber increases, and the pressure in the spool control pressure chamber quickly becomes lower than the predetermined value. As a result, the movable discharge valve is quickly moved from the operating position to the non-operating position.
[0021]
That is, the capacity control valve constitutes spool control means, and when refrigerant circulation on the external refrigerant circuit is prevented, the amount of refrigerant gas introduced from the high pressure region through the spool air supply passage is reduced, and The amount of the refrigerant gas led out through the extraction passage is increased, and the pressure in the spool control pressure chamber is lowered below a predetermined value.
[0022]
In addition, if the refrigerant circulation prevention means permits refrigerant circulation on the external refrigerant circuit, and the capacity control valve reduces the opening of the capacity changing air supply passage to change the discharge capacity from the minimum capacity to the non-minimum capacity, The opening degree of the extraction passage is also reduced. Accordingly, the amount of refrigerant gas led out from the spool control pressure chamber to the crank chamber is reduced, and the pressure in the spool control pressure chamber is equal to the amount of refrigerant gas introduced from the high pressure region via the spool air supply passage. By the increase, it quickly becomes higher than the predetermined value. As a result, the movable discharge valve in the inactive position is quickly moved to the operating position.
[0023]
In the invention of claim 4, the capacity changing air supply passage also serves as the spool air supply passage and the spool bleed passage. Therefore, it is not necessary to provide the spool supply passage and the spool extraction passage exclusively.
[0024]
In the fifth aspect of the present invention, when refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means, the capacity control valve reduces the opening of the capacity changing extraction passage from the crank chamber to the suction pressure region. The amount of refrigerant gas discharged to the engine is reduced, and the pressure in the crank chamber is increased. Therefore, the cam plate is tilted to the minimum inclination angle, and the discharge capacity is minimized.
[0025]
Here, the spool air supply passage is routed through a capacity control valve. When the capacity control valve decreases the opening degree of the capacity changing extraction passage, the opening degree of the spool air supply path also decreases. Accordingly, the amount of high-pressure refrigerant gas introduced from the crank chamber to the spool control pressure chamber is reduced, and the pressure of the spool control pressure chamber is reduced by the derivation of the refrigerant gas to the suction pressure region via the spool bleed passage. It quickly becomes lower than the predetermined value. As a result, the movable discharge valve is quickly placed at the inoperative position.
[0026]
That is, the capacity control valve constitutes a spool control means, and when refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation prevention means, the amount of refrigerant gas introduced from the high pressure region via the spool supply passage is reduced. The pressure in the spool control pressure chamber is reduced below a predetermined value.
[0027]
Further, when the refrigerant circulation prevention means permits refrigerant circulation on the external refrigerant circuit, and the capacity control valve increases the opening of the capacity changing bleed passage to change the discharge capacity from the minimum capacity to the non-minimum capacity, the discharge pressure region As the pressure increases, the opening of the air supply passage for the spool also increases. Accordingly, the amount of refrigerant gas introduced from the discharge pressure region into the spool control pressure chamber increases, and the pressure in the spool control pressure chamber quickly becomes higher than the predetermined value. As a result, the movable discharge valve in the inactive position is quickly moved to the operating position.
[0028]
In the invention of claim 6, the capacity changing extraction passage also serves as the spool supply passage and the spool extraction passage. Therefore, it is not necessary to provide the spool supply passage and the spool extraction passage exclusively.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, first and second embodiments in which the present invention is embodied in a clutchless type variable displacement compressor will be described. In the second embodiment, only differences from the first embodiment will be described, and the same or corresponding members will be denoted by the same reference numerals and description thereof will be omitted.
[0030]
(First embodiment)
As shown in FIG. 1, the front housing 11 is bonded and fixed to the front end of the cylinder block 12. The rear housing 13 is joined and fixed to the rear end of the cylinder block 12 via a valve forming body 14. The front housing 11, the cylinder block 12, and the rear housing 13 are the housing components of this embodiment. The crank chamber 15 is defined by being surrounded by the front housing 11 and the cylinder block 12. The drive shaft 16 is rotatably supported between the front housing 11 and the cylinder block 12 so as to pass through the crank chamber 15. The pulley 17 is rotatably supported on the front wall surface of the front housing 11 via an angular bearing 18. The pulley 17 is connected to a projecting end portion of the drive shaft 16 from the front housing 11, and an electromagnetic clutch or the like is connected to a vehicle engine E as an external drive source via a belt 19 wound around the outer peripheral portion. It is operatively connected without any clutch mechanism.
[0031]
The lip seal 21 is interposed between the front end side outer peripheral surface of the drive shaft 16 and the front housing 11 and seals the drive shaft 16.
The rotary support 22 is fixed to the drive shaft 16 in the crank chamber 15. The thrust bearing 44 is interposed between the rotary support 22 and the front housing 11. The swash plate 23 as a cam plate is supported so as to be slidable and tiltable with respect to the drive shaft 16 in the direction of the axis L thereof. The support arm 24 protrudes from the rotary support 22 and is engaged with a spherical portion 25a of a guide pin 25 provided on the swash plate 23 through a guide hole 24a.
[0032]
The swash plate 23 can be tilted in the direction of the axis L of the drive shaft 16 and can rotate integrally with the drive shaft 16 by the linkage of the support arm 24 and the guide pin 25. The tilting of the swash plate 23 is guided by the slide guide relationship between the guide hole 24 a and the spherical portion 25 a and the slide support action of the drive shaft 16. When the radius center portion of the swash plate 23 is moved to the cylinder block 12 side, the inclination angle of the swash plate 23 is reduced. The circlip 20 is fixed to the drive shaft 16 between the swash plate 23 and the cylinder block 12, and the swash plate 23 tilts and comes into contact with the swash plate 23, so that the swash plate 23 is not zero (0 °). Define the tilt angle. The inclination-decreasing spring 26 is interposed between the rotary support 22 and the swash plate 23. The same inclination-decreasing spring 26 urges the swash plate 23 in the direction of decreasing the inclination. The tilt angle restricting projection 23 a is projected from the front surface of the swash plate 23 and is in contact with the rear surface of the rotation support 22, thereby defining the maximum tilt angle of the swash plate 23.
[0033]
As shown in FIG. 2, the cylinder bores 12a are formed at predetermined intervals in a plurality of locations (five locations) on the same circumference in the cylinder block 12, and the same number of single-headed pistons 36 are provided in each cylinder bore 12a. Contained. The swash plate 23 is connected to the piston 36 via a shoe 37, and the rotational motion of the swash plate 23 is converted into the reciprocating linear motion of the piston 36.
[0034]
The suction chamber 38 constituting the suction pressure region is defined in the outer peripheral portion in the rear housing 13. The discharge chamber 39 constituting the discharge pressure region is defined in the inner peripheral portion within the rear housing 13. The suction passage 32 is provided in the rear housing 13 and is connected to the suction chamber 38.
[0035]
The same number of suction holes 40 are formed in the outer peripheral portion of the valve forming body 14 so as to correspond to the cylinder bores 12 a and connect the cylinder bores 12 a and the suction chamber 38. The suction valve 41 is formed corresponding to the suction hole 40 in the valve forming body 14 and opens and closes the suction hole 40. As the piston 36 moves from the top dead center position to the bottom dead center position, refrigerant gas is sucked into the cylinder bores 12 a from the suction chamber 38 through the suction holes 40 by the action of the suction valve 41. .
[0036]
The same number of discharge holes 42 as the cylinder bores 12 a are provided in the inner periphery of the valve forming body 14 to connect the cylinder bores 12 a and the discharge chambers 39. At least one (one in this embodiment) fixed discharge valve 43 is provided in the valve forming body 14 and opens and closes the corresponding discharge hole 42. As the piston 36 moves from the bottom dead center position to the top dead center position, the action of the fixed discharge valve 43 compresses the refrigerant gas in the corresponding cylinder bore 12a to a predetermined pressure, The ink is discharged into the discharge chamber 39 through the discharge hole 42.
[0037]
The passage 46 is formed in the drive shaft 16, the inlet 46 a is near the lip seal 21 on the front end side of the drive shaft 16, and the outlet 46 b is a cylinder block that supports the rear end side of the drive shaft 16 via the radial bearing 30. Each of the twelve receiving holes 27 is opened.
[0038]
The capacity changing bleed passage 47 is formed in the cylinder block 12 and the valve forming body 14 and connects the accommodation hole 27 which is a part of the crank chamber 15 and the suction chamber 38 as a suction pressure region. The capacity changing air supply passage 48 connects a discharge chamber 39 serving as a discharge pressure region and the crank chamber 15, and a capacity control valve 49, which is a pressure sensitive valve, is interposed on the passage 48. The same volume control valve 49 will be described. The valve chamber 50 constitutes a part of the capacity changing air supply passage 48, and a port 50 a is formed in the valve chamber 50. The valve body 51 is accommodated in the valve chamber 50 and is urged by a spring 56 in a direction in contact with the port 50a. The storage chamber 52 is partitioned from the valve chamber 50. By partitioning the storage chamber 52 with a diaphragm 53 that is a pressure-sensitive member, a pressure-sensitive chamber 52a and an atmospheric chamber 52b that is open to the atmosphere are formed. Yes. The valve body 51 and the diaphragm 53 are connected via a rod 54. The pressure detection passage 55 connects the suction chamber 38 and the pressure sensing chamber 52a, and introduces the refrigerant gas in the suction chamber 38 into the pressure sensing chamber 52a.
[0039]
Accordingly, the diaphragm 53 is operated depending on the pressure in the suction chamber 38, and the opening degree of the port 50a, that is, the opening degree of the capacity changing air supply passage 48 is adjusted by the valve body 51. For this reason, the amount of high-pressure refrigerant gas introduced into the crank chamber 15 is changed, and the pressure in the crank chamber 15 is changed. As a result, the difference between the pressure in the crank chamber 15 acting before and after the piston 36 and the pressure in the cylinder bore 12a is adjusted. Therefore, the inclination angle of the swash plate 23 is changed, the stroke of the piston 36 is changed, and the discharge capacity is adjusted.
[0040]
An electromagnetic valve 57 as refrigerant circulation blocking means is interposed on the suction passage 32 in the rear housing 13, and the valve body 57b closes the passage 32 by demagnetization of the solenoid 57a, and the valve body 57b is the same by excitation of the solenoid 57a. The passage 32 is opened.
[0041]
In the compressor configured as described above, the suction passage 32 and the discharge chamber 39 are connected by an external refrigerant circuit 71. The condenser 72, the expansion valve 73 and the evaporator 74 are interposed on the external refrigerant circuit 71.
[0042]
The evaporator temperature sensor 81, the passenger compartment temperature sensor 82, the air conditioner switch 83, the passenger compartment temperature setter 84, and the solenoid 57 a of the electromagnetic valve 57 are connected to the control computer 85. The control computer 85 excites the solenoid valve 57 (solenoid 57a) based on input values such as detection values by the sensors 81 and 82, an on / off signal of the air conditioner switch 83, a set temperature signal by the passenger compartment temperature setter 84, and the like.・ Demagnetize.
[0043]
Next, features of the present embodiment will be described.
The spring accommodating hole 58 is formed in the center portion from the cylinder block 12 to the valve forming body 14 and is opened to the discharge chamber 39. A cylindrical spool support portion 59 projects from the center of the inner wall surface of the rear housing 13 in the discharge chamber 39. The spool 60 having a bottomed cylindrical shape is fitted and supported by the spool support portion 59. The spool 60 is slidable in the approaching / separating direction with respect to the valve forming body 14 by being guided by the spool support portion 59.
[0044]
The movable discharge valve 61 is fixed on the front side of the spool 60 together with a retainer 62 for defining the opening degree. The movable discharge valve 61 is moved between an operating position in contact with the center of the back surface of the valve forming body 14 and an inactive position spaced from the valve forming body 14 in conjunction with the sliding movement of the spool 60. The A plurality (four) of opening / closing portions 61a are formed radially on the outer peripheral portion of the movable discharge valve 61, and the opening / closing portion 61a corresponds to the remaining discharge holes 42 to which the fixed discharge valve 43 does not correspond. The opening / closing portion 61a performs the same operation as the fixed discharge valve 43 when the movable discharge valve 61 is in the operating position, and the refrigerant gas sucked into the cylinder bore 12a is compressed and discharged to the discharge chamber 39. . The opening / closing portion 61a does not function as a discharge valve by always opening the discharge hole 42 in a state where the movable discharge valve 61 is in the inoperative position. That is, the refrigerant gas sucked into the cylinder bore 12a is discharged into the discharge chamber 39 without being compressed.
[0045]
The guide pin 63 is installed between the rear housing 13 and the valve forming body 14 in the discharge chamber 39, and is inserted into the movable discharge valve 61 and a part of the retainer 62 with some play. Yes. Therefore, the movable discharge valve 61 and the retainer 62 are restricted from rotating around their own axis by the guide pin 63 and are only allowed to move in the axial direction.
[0046]
The spring seat 64 is fixed in the spring accommodating hole 58. A spring 65 as an urging means is interposed between the spring seat 64 and the front surface of the movable discharge valve 61. The spring 65 urges the spool 60 rearward so that the movable discharge valve 61 is disposed at the non-operating position.
[0047]
The spool control pressure chamber 66 is defined by being surrounded by a spool support portion 59 on the back side of the spool 60. The seal ring 67 is fitted and fixed to the outer peripheral surface of the spool 60 and is pressed against the inner peripheral surface of the spool support portion 59 in an annular region, thereby sealing the spool control pressure chamber 66 from the discharge chamber 39. .
[0048]
Here, in the capacity changing air supply passage 48, a portion located on the discharge chamber 39 side from the capacity control valve 49 (port 50 a) passes through the spool control pressure chamber 66. That is, in the same passage 48, the first passage 48 a that connects the discharge chamber 39 as the high pressure region and the spool control pressure chamber 66 forms the spool air supply passage of the present embodiment, and the spool control pressure chamber 66. And a second passage 48b connecting the crank chamber 15 as a low pressure region constitutes a spool extraction passage.
[0049]
Next, the operation of the compressor configured as described above will be described.
The control computer 85 excites the electromagnetic valve 57 when the detected value of the passenger compartment temperature sensor 82 is equal to or higher than the preset temperature of the passenger compartment temperature setter 84 with the air conditioner switch 83 turned on. Accordingly, the suction passage 32 is opened, and the introduction of the refrigerant gas from the external refrigerant circuit 71 to the suction chamber 38 is allowed. As a result, the capacity control valve 49 performs discharge capacity control based on the pressure (suction pressure) of the refrigerant gas in the suction chamber 38 introduced into the pressure sensing chamber 52a.
[0050]
For example, when the cooling load is large, the suction pressure becomes higher than the set value, and the capacity control valve 49 is operated so as to reduce the opening degree of the capacity changing supply passage 48. Accordingly, the pressure in the crank chamber 15 is released and reduced to the suction chamber 38 via the passage 46 and the capacity changing bleed passage 47, and the inclination angle of the swash plate 23 is changed to the maximum inclination side so that the stroke amount of the piston 36 is increased. Becomes larger. As a result, the discharge capacity is increased and the suction pressure is reduced.
[0051]
When the cooling load is small, the suction pressure becomes lower than the set value, and the capacity control valve 49 is operated so as to increase the opening of the capacity changing supply passage 48. Accordingly, the pressure in the crank chamber 15 is increased by the introduction of the high-pressure refrigerant gas, the inclination angle of the swash plate 23 is changed to the minimum inclination side, and the stroke amount of the piston 36 is reduced. As a result, the discharge capacity is reduced and the suction pressure is increased.
[0052]
As described above, the capacity control valve 49 changes the discharge capacity by changing the inclination angle of the swash plate 23 in order to maintain the suction pressure set by the specifications of the spring 56, the diaphragm 53, and the like.
[0053]
At this time, if the displacement control valve 49 does not control the discharge capacity to the minimum, the opening degree of the second passage 48b does not become the maximum, and the crank chamber 15 passes from the spool control pressure chamber 66 through the second passage 48b. The amount of refrigerant gas led to is small. Further, since the discharge capacity is not minimum, the pressure in the discharge chamber 39 is high, and the amount of refrigerant gas introduced from the discharge chamber 39 into the spool control pressure chamber 66 through the first passage 48a is large. Therefore, the pressure in the spool control pressure chamber 66 is maintained higher than a predetermined value, the spool 60 is brought close to the valve forming body 14 in balance with the urging force of the spring 65, and the movable discharge valve 61 is disposed at the operating position. The Therefore, the refrigerant gas is compressed in all the cylinder bores 12a, and the required amount of high-pressure refrigerant gas is reliably supplied to the external refrigerant circuit 71.
[0054]
Further, when the capacity control valve 49 controls the discharge capacity to the minimum, the pressure in the discharge chamber 39 decreases, and the amount of refrigerant gas introduced from the discharge chamber 39 into the spool control pressure chamber 66 through the first passage 48a. Will be less. Further, the opening degree of the second passage 48b is maximized, and the amount of refrigerant gas led out from the spool control pressure chamber 66 to the crank chamber 15 through the second passage 48b increases. Accordingly, the pressure in the spool control pressure chamber 66 becomes lower than a predetermined value, the spool 60 is separated from the valve forming body 14 due to the balance with the urging force of the spring 65, and the movable discharge valve 61 is disposed at the non-operating position. Is done. Accordingly, the refrigerant gas is not compressed in the cylinder bore 12a to which the movable discharge valve 61 corresponds. However, in the cylinder bore 12 a to which the fixed discharge valve 43 is associated, the refrigerant gas is continuously compressed, and the compressed refrigerant gas is not supplied to the external refrigerant circuit 71. In other words, since the movable discharge valve 61 and the fixed discharge valve 43 are used together, the basic function as a compressor is maintained even at the minimum discharge capacity.
[0055]
Now, as shown in FIG. 3, as the temperature approaches the state where there is no cooling load, the temperature in the evaporator 74 approaches the temperature that causes frost generation. The control computer 85 demagnetizes the solenoid valve 57 when the evaporator temperature falls below the frost determination temperature. The frost determination temperature reflects a situation where frost is likely to occur in the evaporator 74. Further, the control computer 85 demagnetizes the electromagnetic valve 57 when the air conditioner switch 83 is switched to the OFF state.
[0056]
Thus, when the solenoid valve 57 is demagnetized, the suction passage 32 is closed, the introduction of the refrigerant gas from the external refrigerant circuit 71 to the suction chamber 38 is stopped, and refrigerant circulation on the external refrigerant circuit 71 is prevented. Accordingly, the suction pressure introduced into the pressure sensing chamber 52a of the capacity control valve 49 is greatly reduced below the set value, and the valve body 51 maximizes the port 50a, that is, the second passage 48b of the capacity control air supply passage 48. Transition to the open valve position. For this reason, a large amount of the high-pressure refrigerant gas in the discharge chamber 39 is supplied to the crank chamber 15, and the pressure in the crank chamber 15 increases. As a result, the swash plate 23 is tilted to the minimum inclination angle to minimize the discharge capacity, and the movable discharge valve 61 is moved from the operating position to the non-operating position as described above.
[0057]
Since the minimum inclination angle of the swash plate 23 is not zero, the piston 36 continues reciprocating linear motion with a small amount. The fixed type discharge valve 43 continues to function as a discharge valve even after the movable type discharge valve 61 is disposed at the non-operating position, and the refrigerant gas is compressed in the cylinder bore 12a to which the valve 43 corresponds. Therefore, the refrigerant gas discharged from the cylinder bore 12a to the discharge chamber 39 is not discharged to the external refrigerant circuit 71 in the refrigerant circulation inhibition state, but flows into the crank chamber 15 through the capacity changing supply passage 48. . The refrigerant gas in the crank chamber 15 flows into the suction chamber 38 through the passage 46 and the extraction passage 47. The refrigerant gas in the suction chamber 38 is sucked into the cylinder bore 12a and discharged again into the discharge chamber 39.
[0058]
That is, in a state where the suction passage 32 is closed by the electromagnetic valve 57, the discharge chamber 39 → the capacity changing air supply passage 48 → the crank chamber 15 → the passage 46 → the receiving hole 27 → the capacity changing bleed passage 47 → the suction chamber 38 → A circulation passage through the cylinder bore 12a → the discharge chamber 39 is formed in the compressor. Since the refrigerant gas is compressed in the cylinder bore 12a to which the fixed discharge valve 43 corresponds, a pressure difference is generated among the discharge chamber 39, the crank chamber 15 and the suction chamber 38. Accordingly, the refrigerant gas circulates in the circulation passage, and the lubricating oil that flows together with the refrigerant gas lubricates each sliding portion in the compressor.
[0059]
In the state where the air conditioner switch 83 is on and the swash plate 23 is at the minimum tilt position, for example, when the passenger compartment temperature rises and the cooling load increases, the passenger compartment temperature detected by the passenger compartment temperature sensor 82 is increased. The set temperature of the passenger compartment temperature setter 84 is exceeded. The control computer 85 excites the electromagnetic valve 57 based on the displacement of the passenger compartment temperature, and the suction passage 32 is opened. At this time, the suction pressure is higher than the set value, and the capacity control valve 49 decreases the opening degree of the second passage 48b of the capacity changing air supply passage 48 and tilts the swash plate 23 to the maximum inclination side. Therefore, as described above, the movable discharge valve 61 in the non-operating position is disposed in the operating position.
[0060]
When the vehicle engine E is stopped, the operation of the compressor is also stopped, that is, the rotation of the swash plate 23 is stopped, and the energization to the electromagnetic valve 57 is also stopped. Therefore, the suction passage 32 is closed, the pressure in the suction chamber 38 is reduced, and the second passage 48b of the capacity control supply passage 48 is opened to the maximum by the capacity control valve 49. Accordingly, the inclination angle of the swash plate 23 is minimized and the movable discharge valve 61 is moved from the operating position to the non-operating position. If the operation stop state of the compressor continues, the pressure in the compressor becomes uniform, but the inclination angle of the swash plate 23 is held at a small inclination angle by the urging force of the inclination reduction spring 26. When the operation of the compressor is started by starting the vehicle engine E, the swash plate 23 starts rotating from the minimum inclination state with the smallest load torque, and the cylinder bore 12a to which the movable discharge valve 61 is associated. There is no compression work inside. Therefore, the shock at the start of the compressor is effectively reduced.
[0061]
In this embodiment having the above-described configuration, the following effects can be obtained.
(1) When the circulation of the refrigerant on the external refrigerant circuit 71 is blocked by the demagnetization of the electromagnetic valve 57, the movable discharge valve 61 is disposed at the inoperative position. Therefore, compression work is not performed in the cylinder bore 12a to which the movable discharge valve 61 corresponds, and power loss can be effectively reduced. In addition, the compression reaction force hardly acts on the piston 36 in the cylinder bore 12a to which the movable discharge valve 61 corresponds, and the piston 36 is not pressed against the cylinder bore 12a. Therefore, in the minimum discharge capacity state, the sliding resistance between the piston 36 and the cylinder bore 12a is reduced, and wear deterioration can be prevented.
[0062]
(2) The capacity control valve 49 minimizes the discharge capacity when refrigerant circulation on the external refrigerant circuit 71 is prevented by demagnetization of the electromagnetic valve 57. Therefore, the above (1) is more effectively achieved.
[0063]
(3) The capacity control valve 49 minimizes the discharge capacity when refrigerant circulation on the external refrigerant circuit 71 is prevented by demagnetization of the electromagnetic valve 57. When the discharge capacity is minimized, the pressure in the discharge chamber 39 is reduced, and the amount of refrigerant gas introduced from the discharge chamber 39 into the spool control pressure chamber 66 via the spool air supply passage (first passage 48a) decreases. . That is, the same capacity control valve 49 constitutes a spool control means, and reduces the pressure of the spool control pressure chamber 66 according to the refrigerant circulation prevention on the external refrigerant circuit 71. For this reason, in order to reduce the pressure of the spool control pressure chamber 66 according to the refrigerant circulation prevention on the external refrigerant circuit 71, it is not necessary to provide a dedicated spool control means. As a result, the unload mechanism of the movable discharge valve 61 can be configured easily and inexpensively.
[0064]
(4) The spool extraction passage (second passage 48 b) connects the spool control pressure chamber 66 and the crank chamber 15. Therefore, when the circulation of the refrigerant on the external refrigerant circuit 71 is blocked by the demagnetization of the electromagnetic valve 57, the refrigerant gas in the spool control pressure chamber 66 is led out to the crank chamber 15 through the second passage 48b. As a result, the pressure in the spool control pressure chamber 66 is quickly reduced below a predetermined value, and the movable discharge valve 61 is quickly moved from the operating position to the non-operating position.
[0065]
(5) The spool extraction passage (second passage 48 b) is routed through the capacity control valve 49. Accordingly, the same capacity control valve 49 as a spool control means also adjusts the amount of refrigerant gas led out from the spool control pressure chamber 66 to the crank chamber 15 via the second passage 48b. That is, when refrigerant circulation on the external refrigerant circuit 71 is blocked, the amount of refrigerant gas led out from the spool control pressure chamber 66 to the crank chamber 15 via the second passage 48b increases. Accordingly, the pressure in the control pressure chamber 66 for the spool is further rapidly reduced, and the movable discharge valve 61 is moved more rapidly from the operating position to the non-operating position. Further, when the refrigerant circulation on the external refrigerant circuit 71 is allowed, the amount of refrigerant gas led out from the spool control pressure chamber 66 to the crank chamber 15 via the second passage 48b decreases. Accordingly, the pressure in the spool control pressure chamber 66 is quickly increased, and the movable discharge valve 61 is quickly moved from the non-operating position to the operating position, so that the original function of the compressor is quickly exhibited. As described above, the response of the movable discharge valve 61 to the change of the refrigerant circulation state on the external refrigerant circuit 71 is improved.
[0066]
(6) The capacity changing air supply passage 48 passes through the spool control pressure chamber 66 on the discharge chamber 39 side of the capacity control valve 49, and the first passage 48a of the passage 48 is the spool air supply passage. The passages 48b also serve as spool extraction passages. Therefore, it is not necessary to form a dedicated passage for the unloading mechanism of the movable discharge valve 61, and the mechanism can be configured easily and inexpensively.
[0067]
(7) The drive shaft 15 is operatively connected to the vehicle engine E without an expensive and heavy clutch mechanism such as an electromagnetic clutch. Therefore, the cost and weight of the compressor can be reduced. In addition, the deterioration of the feeling of feeling due to on / off of the electromagnetic clutch can be solved simultaneously.
[0068]
(Second Embodiment)
FIG. 4 shows a second embodiment. In the first embodiment, the crank chamber 15 is regulated by adjusting the amount of high-pressure refrigerant gas introduced from the discharge chamber 39. However, the present embodiment is different in that the pressure in the crank chamber 15 is regulated by adjusting the amount of refrigerant gas led out to the suction chamber 38.
[0069]
That is, the capacity changing air supply passage 91 connects the discharge chamber 39 and the accommodation hole 27 which is a part of the crank chamber 15. The capacity changing extraction passage 92 connects the crank chamber 15 and the suction chamber 38, and a capacity control valve 93 is interposed on the passage 92. The operation of the valve body 51 according to the height of the set value of the suction pressure is opposite to that of the capacity control valve 49 of the first embodiment.
[0070]
That is, when the suction pressure is higher than the set value, the valve body 51 is separated from the port 50a, and the opening degree of the capacity changing bleed passage 92 is increased. Accordingly, the pressure in the crank chamber 15 is released and reduced to the suction chamber 38 via the same capacity changing bleed passage 92, and the swash plate 23 is tilted to the maximum inclination side.
[0071]
When the suction pressure is lower than the set value, the valve body 51 is brought close to the port 50a, and the opening degree of the capacity changing bleed passage 92 is reduced. Therefore, the pressure in the crank chamber 15 is increased by the introduction of the high-pressure refrigerant gas through the capacity changing supply passage 91, and the swash plate 23 is tilted to the minimum inclination side.
[0072]
In the present embodiment, the capacity control bleed passage 92 is located via the spool control pressure chamber 66 at a portion located on the suction chamber 38 side of the capacity control valve 93 (port 50a). Accordingly, in the passage 92, the first passage 92a connecting the crank chamber 15 as the high pressure region and the spool control pressure chamber 66 forms the spool air supply passage of the present embodiment, and the spool control pressure chamber 66 is provided. The second passage 92b connecting the suction chamber 38 and the suction chamber 38 as a low pressure region forms a spool extraction passage.
[0073]
Here, for example, when the displacement control valve 93 sets the discharge capacity to a non-minimum, the first passage 92a is opened, and the spool control pressure chamber 66 is introduced by introducing the high-pressure refrigerant gas from the crank chamber 15 through the first passage 92a. The pressure becomes higher than a predetermined value. Therefore, the spool 60 is brought close to the valve forming body 14 in balance with the urging force of the spring 65, and the movable discharge valve 61 is arranged at the operating position.
[0074]
When the capacity control valve 93 minimizes the discharge capacity, the first passage 92a is closed and the introduction of the high-pressure refrigerant gas from the crank chamber 15 through the first passage 92a is stopped. Accordingly, the pressure in the spool control pressure chamber 66 becomes lower than a predetermined value due to the derivation of the refrigerant gas to the suction chamber 38 via the second passage 92b. Therefore, the spool 60 is separated from the valve forming body 14 by the balance with the urging force of the spring 65, and the movable discharge valve 61 is disposed at the non-operating position.
[0075]
As described above, in the present embodiment, when the solenoid valve 57 is demagnetized, the capacity changing extraction passage 92 is closed to minimize the discharge capacity, and the passage 92 constitutes the refrigerant gas circulation passage described above. It becomes impossible. Accordingly, the extraction passage 94 having the throttle 94a connects the crank chamber 15 and the suction chamber 38 to form a circulation passage, and the passage 94 is connected to the crank chamber 15 during the internal circulation of the refrigerant gas containing the lubricating oil. It serves to guide the refrigerant gas inside to the suction chamber 38. Since the capacity changing air supply passage 91 is connected to the accommodation hole 27, the positional relationship between the inlet 46a and the outlet 46b of the passage 46 is opposite to that in the first embodiment.
[0076]
In the present embodiment having the above-described configuration, the same effects as the effects (1), (2), (4), and (7) of the first embodiment are exhibited, and the following effects are also achieved.
(1) The spool air supply passage (first passage 92 a) passes through the capacity control valve 93. Accordingly, the same capacity control valve 93 serves as a spool control means for adjusting the amount of refrigerant gas introduced from the crank chamber 15 into the spool control pressure chamber 66 via the first passage 92a. That is, when the refrigerant circulation on the external refrigerant circuit 71 is blocked, the first passage 92a is closed, and the introduction of the refrigerant gas from the crank chamber 15 to the spool control pressure chamber 66 is stopped. Accordingly, the pressure in the spool control pressure chamber 66 is quickly reduced below the predetermined value without waiting for the pressure drop in the discharge chamber 39, and the movable discharge valve 61 is quickly moved from the operating position to the non-operating position. When the refrigerant circulation on the external refrigerant circuit 71 is permitted, the opening degree of the first passage 92a is increased, and the refrigerant introduced from the crank chamber 15 to the spool control pressure chamber 66 through the first passage 92a. The amount of gas increases. Accordingly, the pressure in the spool control pressure chamber 66 is quickly increased, and the movable discharge valve 61 is quickly moved from the non-operating position to the operating position, so that the original function of the compressor is quickly exhibited. As described above, the response of the movable discharge valve 61 to the change of the refrigerant circulation state on the external refrigerant circuit 71 is improved.
[0077]
(2) The capacity changing bleed passage 92 passes through the spool control pressure chamber 66 on the suction chamber 38 side from the capacity control valve 93, and the first passage 92a of the passage 92 serves as the spool air supply passage. 92b doubles as a spool extraction passage. Therefore, it is not necessary to form a dedicated passage for the unloading mechanism of the movable discharge valve 61, and the mechanism can be configured easily and inexpensively.
[0078]
In addition, this invention is not limited to the said embodiment, For example, it can implement also in the following aspects.
(1) In the first embodiment, the spool supply passage and the spool bleed passage are provided completely independently from the capacity changing supply passage 48, and the opening degree is adjusted on the spool bleed passage. A dedicated external control valve may be provided as spool control means. Further, in the second embodiment, the spool supply passage and the spool extraction passage are provided completely independently from the capacity changing extraction passage 92, and the opening degree is adjusted on the spool supply passage 92. A dedicated external control valve may be provided as spool control means. In this way, it is possible to arbitrarily dispose the movable discharge valve 61 at the non-operating position other than at the minimum discharge capacity.
[0079]
(2) In the above embodiment, the movable discharge valve 61 is operated by changing the pressure in the spool control pressure chamber 66. However, the present invention is not limited to this, and the movable discharge valve 61 may be configured to be operated by an actuator such as an electromagnetic mechanism. In this way, it is possible to arbitrarily dispose the movable discharge valve 61 at the non-operating position other than at the minimum discharge capacity.
[0080]
(3) In the above embodiment, the movable discharge valve 61 is moved between the operating position and the non-operating position by being brought into contact with and separated from the valve forming body 14. By changing this, the movable discharge valve 61 may be configured to move between the operating position and the non-operating position by rotating about its own axis.
[0081]
(4) The spool control pressure chamber 66 and the high pressure region (for example, the discharge chamber 39, the crank chamber 15 and the like) are simply connected by the spool air supply passage. Then, the spool 60 is operated only by the pressure change in the high pressure region by changing the discharge capacity. That is, when the discharge capacity is minimized, the pressure in the high pressure region is reduced, and the pressure in the spool control pressure chamber 66 becomes lower than a predetermined value. Accordingly, the spool 60 is moved away from the valve forming body 14 in balance with the urging force of the spring 65, and the movable discharge valve 61 is disposed from the operating position to the non-operating position. When the discharge capacity is increased from this state, the pressure in the high pressure region is increased, and the pressure in the spool control pressure chamber 66 becomes higher than a predetermined value. Accordingly, the spool 60 is moved close to the valve forming body 14 in balance with the biasing force of the spring 65, and the movable discharge valve 61 is disposed from the non-operating position to the operating position. In this way, since the unload mechanism of the movable discharge valve 61 is not required, a passage configuration other than the spool air supply passage is not required, and the mechanism can be configured easily and inexpensively. Further, since the spool air supply passage is not passed through the capacity control valve as in the first embodiment, for example, there is a degree of freedom in its operation in the housing.
[0082]
(5) In the above (4), the spool control pressure chamber 66 and the low pressure region (for example, the crank chamber 15 with respect to the discharge chamber 39 and the suction chamber 38 with respect to the crank chamber 15) are connected to the spool bleed passage. Connect by. In other words, the control pressure chamber for the spool is based on the balance between the change in the amount of refrigerant gas introduced from the high pressure region and the amount of refrigerant gas introduced into the low pressure region through the spool extraction passage due to the pressure change in the high pressure region. Adjust the pressure in 66. In this way, when the discharge capacity is minimized, the pressure in the spool control pressure chamber 66 is quickly reduced below a predetermined value via the spool bleed passage, and from the operating position of the movable discharge valve 61. Movement to the inactive position is made quickly.
[0083]
(6) The present invention is embodied in a compressor in which capacity control valves 49 and 92 are provided in both the supply passage 48 and the extraction passage 91. That is, the crank chamber 15 is regulated by adjusting the amount of high-pressure refrigerant gas introduced from the discharge chamber 39 and adjusting the amount of refrigerant gas led out to the suction chamber 38. In this case, the pressure in the spool control pressure chamber 66 may be adjusted as in the first embodiment or as in the second embodiment. Furthermore, the method of combining the first and second embodiments, that is, changing the pressure of the spool control pressure chamber 66 is performed by adjusting both the amount of refrigerant gas introduced into the chamber 66 and the amount of derivation thereof. You may comprise.
[0084]
(7) The above embodiment is embodied in a compressor that performs capacity control by adjusting the pressure in the crank chamber 15. However, the present invention is not limited to this, and may be embodied in a compressor that performs capacity control by adjusting the pressure in the cylinder bore 12a. In this case, a control pressure chamber for changing capacity is provided separately from the crank chamber 15, and the pressure of the refrigerant gas flowing into the cylinder bore 12a is adjusted by adjusting the pressure of the control pressure chamber.
[0085]
(8) To be embodied in a wobble type variable capacity compressor.
(9) To be embodied in a variable displacement compressor with a clutch.
When technical ideas other than those described in the claims that can be grasped from the above embodiment are described, when the refrigerant circulation on the external refrigerant circuit 71 is blocked by the refrigerant circulation blocking means 57, the cam plate 23 is tilted to the minimum inclination angle. The variable capacity compressor according to claim 2, further comprising capacity control means (49) for minimizing discharge capacity, wherein the capacity control means (49) constitutes the spool control means.
[0086]
In this way, there is no need for a dedicated spool control means for disposing the movable discharge valve 61 at the non-operating position in accordance with refrigerant circulation inhibition. Therefore, the unloading mechanism of the movable discharge valve 61 can be configured easily and inexpensively.
[0087]
【The invention's effect】
According to the first and second aspects of the present invention, for example, when cooling is not required or when frost is likely to occur in the evaporator of the external refrigerant circuit, the refrigerant circulation on the external refrigerant circuit is prevented by the refrigerant circulation prevention means. Be blocked. At this time, the movable discharge valve is disposed at the non-operating position by the unloading means, and the refrigerant gas is not compressed in the cylinder bore corresponding to the valve, thereby reducing the power loss.
[0088]
In addition, since the refrigerant circulation on the external refrigerant circuit is prevented, the compressor operation may be continued even when cooling is unnecessary or when frost is likely to occur in the evaporator of the external refrigerant circuit. Therefore, in the invention of claim 7, the drive shaft is operatively connected to the external drive source without using an expensive and heavy clutch mechanism such as an electromagnetic clutch. Therefore, the cost and weight of the compressor can be reduced. In addition, the deterioration of the feeling of feeling due to on / off of the electromagnetic clutch can be solved simultaneously.
[0089]
According to invention of Claim 3 and 5, a capacity | capacitance control valve comprises a spool control means. For this reason, it is not necessary to provide a dedicated spool control means in order to reduce the pressure in the spool control pressure chamber in accordance with the refrigerant circulation prevention on the external refrigerant circuit. Therefore, the unloading mechanism of the movable discharge valve can be configured easily and inexpensively. The capacity control valve minimizes the discharge capacity when refrigerant circulation on the external refrigerant circuit is prevented. Therefore, the reduction of the power loss described above is more effectively achieved.
[0090]
According to the invention of claim 4, the capacity changing air supply passage also serves as the spool air supply passage and the spool bleed passage. Therefore, it is not necessary to form a dedicated passage for adjusting the pressure of the spool control pressure chamber, and the unload mechanism can be configured easily and inexpensively.
[0091]
According to the sixth aspect of the invention, the capacity changing bleed passage also serves as the spool air supply passage and the spool bleed passage. Therefore, it is not necessary to form a dedicated passage for adjusting the pressure of the spool control pressure chamber, and the unload mechanism can be configured easily and inexpensively.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a variable capacity compressor of a clutchless type.
FIG. 2 is a cross-sectional view corresponding to line AA in FIG.
FIG. 3 is a diagram for explaining the operation of the compressor.
FIG. 4 is a longitudinal sectional view of a compressor showing a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Front housing as a housing structure, 12 ... Cylinder block, 12a ... Cylinder bore, 13 ... Rear housing as a housing structure, 14 ... Valve formation body, 15 ... Crank chamber as a low-pressure area, 16 ... Drive shaft, DESCRIPTION OF SYMBOLS 23 ... Swash plate as a cam plate, 38 ... Suction chamber as a suction pressure area, 39 ... Discharge chamber as a high pressure area, 42 ... Discharge hole, 43 ... Fixed discharge valve, 47 ... Unloading means and circulation passage The capacity changing bleed passage, 48 ... same capacity changing air supply passage, 48a ... the first passage as the spool air supply passage, 48b ... the second passage as the spool bleed passage, 49 ... unloading means. Capacity control valve, 57 ... Electromagnetic valve as refrigerant circulation prevention means, 60 ... Spool, 61 ... Movable discharge valve, 65 ... Spring as urging means, 6 ... spool control pressure chamber, 71 ... external refrigerant circuit.

Claims (7)

A drive shaft is rotatably held in a housing formed by joining a plurality of housing components, and a crank chamber for accommodating a suction chamber, a discharge chamber, and a cam plate is defined in the housing, and a piston is provided. A plurality of cylinder bores to be accommodated, and a valve formation having a plurality of discharge holes corresponding to each cylinder bore between the housing structure in which the suction chamber and the discharge chamber are formed and the housing structure in which the cylinder bore is formed A body is interposed, and the cam plate converts the rotational motion of the drive shaft into the reciprocating linear motion of the piston, so that the refrigerant gas is sucked into the cylinder bore from the suction chamber and compressed, and then discharged through the discharge hole. In a variable capacity compressor that can discharge into the chamber and change the discharge capacity by adjusting the tilt angle of the cam plate,
Refrigerant circulation prevention means for preventing refrigerant circulation on the external refrigerant circuit;
A circulation passage for circulating the refrigerant gas through the discharge chamber, the crank chamber and the suction chamber when the refrigerant circulation prevention means prevents the refrigerant circulation on the external refrigerant circuit;
A fixed discharge valve disposed in the valve forming body and corresponding to at least one but not all of the discharge holes on the valve forming body;
A movable discharge valve that can move between an action position that acts as a discharge valve and a non-action position that does not act as a discharge valve, corresponding to the discharge holes other than the corresponding discharge holes.
A variable capacity compressor comprising unloading means for disposing a movable discharge valve at a non-operating position when refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means. The movable discharge valve is configured to be able to contact and separate from the valve forming body, and the unloading means includes:
A spool that is disposed inside the housing and connected to the movable discharge valve, and is movable in the proximity and separation directions with respect to the valve forming body;
A spool control pressure chamber defined on the back side of the spool;
Biasing means for biasing the spool so that the movable discharge valve is separated from the valve forming body;
An air supply passage for the spool connecting the control pressure chamber for the spool and a high pressure region higher than the suction pressure region;
A spool extraction passage connecting the control pressure chamber for the spool and a low pressure region lower than the high pressure region;
When refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means, the amount of refrigerant gas introduced from the high pressure region through the spool air supply passage and / or the spool gas extraction passage is derived. The variable capacity compressor according to claim 1, further comprising spool control means for reducing the pressure of the spool control pressure chamber by adjusting an amount of refrigerant gas. The adjustment of the tilt angle of the cam plate is performed by changing the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston by adjusting the pressure in the crank chamber.
A capacity change air supply passage connecting the discharge pressure area which is a high pressure area and the crank chamber which is a low pressure area;
A capacity change bleed passage connecting the crank chamber and the suction pressure region;
When the refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means by adjusting the pressure of the crank chamber by adjusting the opening degree of the passage, which is interposed on the capacity changing supply passage. With a capacity control valve that increases the opening of the passage and minimizes the discharge capacity,
The variable displacement compressor according to claim 2, wherein the spool bleed passage is routed through a capacity control valve, and the capacity control valve constitutes the spool control means. 4. The capacity change air supply passage is configured such that a portion located on the discharge pressure region side of the capacity control valve is routed through a spool control pressure chamber, and the same passage also serves as a spool air supply passage and a spool bleed passage. The variable capacity compressor described. The adjustment of the tilt angle of the cam plate is performed by changing the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston by adjusting the pressure in the crank chamber.
A capacity change air supply passage connecting the discharge pressure region and the crank chamber which is the high pressure region;
A capacity change bleed passage connecting the crank chamber and a suction pressure area which is a low pressure area;
When the refrigerant circulation on the external refrigerant circuit is blocked by the refrigerant circulation blocking means by changing the crank chamber pressure by adjusting the opening of the same passage and adjusting the opening of the same capacity changing bleed passage A displacement control valve that minimizes the discharge capacity by reducing the opening of
The variable capacity compressor according to claim 2, wherein the spool air supply passage is routed through a capacity control valve, and the capacity control valve constitutes the spool control means. 6. The capacity changing bleed passage is a portion located on the suction pressure region side of the capacity control valve via a spool control pressure chamber, and the passage also serves as a spool air supply passage and a spool bleed passage. Variable capacity compressor. The variable displacement compressor according to claim 1, wherein the drive shaft is operatively connected to an external drive source without a clutch mechanism.

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